Grip device for earth boring apparatus



Oct 31, 1933. J. E. c. cuRRENs GRIP DEVICE FOR EARTH BORING APPARATUS Filed Feb. 24, 1931 2 Sheets-Sheet l III" Hill'.

Oct. 31, 1933. J. E. c. CURRENS GRIP DEVICE FOR EARTH BORING APPARATUS 2 Sheets-Sheet 2 Filed Feb. 24. 1931 Patented Oct. 31, 1933 PATENT OFFICE GRIP DEVICE FOR EARTH BORING APPARATUS James E. C. Currens, San Anselmo, Calif.

Application February 24, 1931. Serial No. 517,935

6 Claims.V (Cl. Z55- 20) This invention relates to earth boring apparatus of the horizontal type, and more particularly to an improved grip device for engaging the boring bar when it is desired to unscrew the sections thereof.

More specifically, the present invention constitutes an improvement over the grip device shown and described in application Serial No. 469,906, filed July 22, 1930 by Alfred E. Englebright, Fred- 10 erick J. Foret and myself. In said prior application is shown earth boring apparatus comprising a track anda carriage movable along such track, on which carriage is mounted the boring bar and a motor for driving the same. At the front end of the track, there is provided a grip device through which, when released, the boring bar can freely move, but which may be actuated to grip and hold the boring bar against rotation,.so-that the sections thereof may be disconnected Vby reversing the direction of rotation ofthe motor.

In said application, there is also disclosed reaming devices adapted to be inserted at any desired point between boring bar sections, and serving to enlarge the hole bored by the auger. construction of grip device shown in said prior application, it was impossible to assemble these reaming sections into the boring bar at the most convenient point to insert them, namely, between the grip device and the carriage, because these reamers, being of relatively large diameter, would not pass through the grip device. Consequently, it was necessary to insert the reamer sections at a point ahead of the machine and beyond the track. This not only required the provision of additional space to make possible the necessary manipulations, but also necessitated the user of hand wrenches to hold the boring bar in order that two adjacent sections might be disconnected for the purpose of inserting a reamer section. The object of the present invention is to over come these objections and disadvantages by providing an improved grip device which may be detachably clamped or secured to' the track and which, furthermore, is split, so that it may be disengaged from the boring bar. In this way, when it is desired to insert a reamer section, the grip device may rst be employed to hold the boring bar so that two adjacent sections may be unscrewed, and so that a reamer section may be inserted at a point between the carriage and grip` device, and subsequently, after such reamer section has been inserted, the grip device may be bodily removed from the track and from engagement with the boring bar, so as to permit the free passage of the reamer section as the carriage moves forwardly.

In order that the invention may be readily understood, reference is had to the accompanying drawings forming part of this specification and 50 in which:

Fig. l is a front elevation of the end `of the track of an earth boring machine, showing my improved grip device mounted thereon;

Fig. 2 is a plan view of the main section or body of said grip device;

Fig. 3 is aside elevation thereof;

Fig. 4 is a plan view of the auxiliary or tilting section of the grip device; l

Fig. 5 is a side elevation thereof;

Fig. 6 is a side elevation of a latch device which I employ to hold the two sections of the grip device together; and y Fig. 7 is a fragmentary plan View on a reduced scale showing the general arrangement of earth boring apparatus in connection with which the present invention is employed.

Referring to the drawings in detail, I have shown a track similar to that disclosed in the said prior application. This track comprises a pair of spaced parallel rails 1 shown as in the form of channel beams having inwardly directed flanges. As in said prior application, the rails are secured inposition by means of kcross ties 2 and braces. Y

As shown in Fig. 7, the complete apparatus comprises a boring bar 30 attached to the forward end of a power shaft bymeans of a grip device 36, such power shaft extending through a water box or hydraulic head 31, for supplying water to the interior of the boring bar. Thepower shaft is driven by a motor 34 which, together with thehydraulic head 31, is mounted upon a suitable carriage32, 33 having'wheels 35 adapted to travel on the rails 1. A rack 1fL is preferably associated with these rails by means` of which the carriage may be propelled, in a manner illustrated, for example, in my copending application Serial No. 514,847, filed February 10, 1931.

My improved grip device comprises a main body or skeleton frame 4 having formed in its upper portion a substantially semi-circular seat 5 of a size adapted to receive the boring bar.

An upper or auxiliary section 7 is provided and has formed in its lower face a similar semi-circular seat 6, these two semi-circular portions serving, when the parts are assembled, to form a circular opening, as shown in Figure l, through which opening the boring bar loosely passes and in which it may turn, as inra bearing.

The upper auxiliary section or jaw 7 is pivotally connected at 8 to the lower or main section 4, such pivotal connection being effected by means of spaced eyes 7at formed at the end of the section 7, and a similar eye 9 formed on the main section 4 and adapted to be received between the eyes 7, a pivot pin passing through the alined eyes. Adjacent the eye 9 is an abutment l0 which serves to limit the pivotal movement of the section or jaw 7 when it is swung to open position, as shown in dotted lines in Fig. 1.

The swingingv section or jaw 7 is provided at its middle with a transverse opening 11 adapted to receive a pivot pin 12, and the jaw 7 itself is formed hollow adjacent such opening so as to provide a recess or chamber 7h (see Fig. 4). Housed within this recess and mounted to turn upon the pin 12 is a cam shaped toothed dog 13 having an operating handle 14 by means of which it may be swung, this device being similar to thatV shown in said prior application. In order to strengthen and reinforce this cam dog, a U-shaped bracket 15 embraces the same and the jaw 7 and is also pivotally mounted at its ends upon the pin 12, as shown in Fig. 1.

In order to latch the main and auxiliary sections ofthe grip device together, I formron the main section or frame 4 adjacent the seat 5 a hook 16, as shown in Fig. 3, and to cooperate with this hook I provide 'a swinging bail 17 pivotally mounted on a pin 18 extendingv transversely through and arranged eccentrically of a cylindrical member 19 to which an operating handle 20 is rigidly secured, as clearly shown in Fig. 6.

At the free end of thev auxiliary section or jaw 7, I provide a pair of spaced slotted openings 21 vand an arcuate seat 22 adjacent and between the same, as shown in Figs. 4 and 5.

It will now be understood that the cylindrical member 19 works against the arcuate seat 22, while the pin 18 works in the slots 21, and that by reason of the eccentric mounting of this pin in the member 19, the bail 17 can iirst be swung into position under thehook 16 and then drawn snugly up against the hook by rotating the handle 20, thereby securely locking the two sections of the grip Ydevice together.

' Referring: to Figs/1 and 3, it will be seen that themain section or frame 4 of the grip device bridges the rails 1, and this frame is preferably formed at itsv ends with seats 23 adapted to fit over the inturned flanges of the rails.

The frame 4 is further provided at its`lower side with a pair of spaced studs 24 Vwhich project downwardly from the under surface thereof, as best shown in Fig. 3, and these stud's't easily into a pair of openingsVv or 4sockets formed in a yoke member25. This yoke member is.' as shown in Fig.v 1, substantially coextensive with the frame 4 ofv the grip device and is arranged to engage underneath the rail flanges.

Extending vertically and centrally through the lower portion of the frame 4 is an` opening 26, as vshown in dotted lines in Fig. 2,'and adapted to register with this opening is a similar but screw threaded opening 28 formed in the yoke 25. A screw` 27, having at its upper end a hand wheel 29 or the like, passes freely down through the opening 26 and 'engages the threads in the opening 28. Thus, when the hand wheel 29 is turned, the yoke 25 is drawn firmly toward the frame 4, being held in position by the studs 24,\and thus clamps the rail flanges between itself and said frame.

From the foregoing, it will be seen that byvirtue of my improved construction, the grip device can be secured in any desired position along the track and may be firmly clamped so as to be held in such position by friction only, without the use of any bolts or-other fastening devices. It will'similarly'be seen that by a mere loosening of the screw 27 the yoke 25 can be released and the entire grip device bodily removed from the track.

It will further be obvious that when it is desired to remove the grip device, as described, the bail 17 willbe disengaged from the hook 16 and the auxiliary section or jaw 7 swung about its pivot 8 into dotted line position so as to clear the boring bar. When the jaw is thus opened, the grip device can, of course, be moved laterally out of engagement with such bar, and thus entirely taken oi the machine.

In conclusion, it will now be appreciated that when it is desired to introduce a reamer section between two boring bar sections, the lever 14 is swung to one side so as to cause the cam dog -13 to engage and grip the bar, and the motor is hen reversed so as to unscrew the desired coupling. The reamer section is then inserted in the usual manner and then the entire grip device is disengaged from the boring bar and removed from the track, so as to afford free passage to 'the reamer section as the carriage and boring bar travel forward. In this Way, the use of hand wrenches, with their attendant dangers to the workmen, is avoided and, furthermore, no extra space invadvance of the machine is required.

What I claim is:

1. Earth'bcring apparatus comprising, in combination, a track, a carriage movable therealong, and a boring bar mounted on the carriage, a grip device for engaging the boring bar, and means whereby said grip device may be detachably secured to said track.

2. Earth boring apparatus comprising, in combination, a pair of track rails, a carriage movable therealong, and a boring bar mounted' on the carriage, a grip device for engaging the boring bar, and means whereby said grip device may be .detachably clamped to said track rails and held in position thereon solely by friction.

3. Earth boring apparatus comprising, in combination, a pair of track rails having flanges, a carriage movable therealong, and a boring bar mounted on the carriage, a grip device for engaging the boring bar, and means whereby said grip device may be detachably clamped to the flanges of said track rails.

4. In earth boring apparatus of the type comprising a track, a carriage movable therealong, and a boring bar mounted on the carriage, the combination with a track comprising a pair of spaced parallelrails having inwardly projecting fianges, of a grip device for engaging the boring bar, said grip device having a frame bridge ing said rails, and ayoke member substantially co-extensive with vsaid frame, and means for clamping said flanges between said frame and yoke member so as to frictionally hold said grip device in any desired position on said track.

5. Earth boring apparatus comprising, in combination, a track, a carriage movable therealong, and a boring bar mounted on the carriage, a grip device for engaging the boring bar, said grip device comprising a pair of separable sections whereby it may be disengagedv laterally from said bar, and means for detachably securing said grip device to said track, so that it may be removed when desired.

6. Earth boring apparatus comprising, in combination, a track, a carriage movable therealong, and a boring bar mounted on the carriage, a grip device for engaging the boring bar, said grip device comprising a pair of hingedly connected separable sections, whereby it may be removed laterally from said boring bar, and means for rigidly and detachably securing said grip device to said track. v JAMES E. C. CURRENS. 

